1. Field of the Invention
The present invention relates generally to communication receivers, and more particularly to intermediate frequency (IF) to baseband frequency signal converters for use in communication receivers.
2. Related Art
Recent advances in digital VLSI (Very Large Scale Integration) technology have been employed in communication receivers to achieve increased processing power and decreased power consumption. As will be appreciated, high processing power, low power consumption receivers are necessary to efficiently and effectively implement many types of communication systems, such as cellular telephone systems.
Conventional radio communication receivers and, specifically, the IF-to-baseband signal converters used therein employ analog-to-digital (A/D) converters to convert a received analog signal to a digital signal. Unfortunately, low-cost, low-power analog-to-digital signal conversion technology has benefited slowly from the advances in digital VLSI technology. This is the case, since mixed-signal CMOS and BiCMOS techniques do not allow for low-power analog signal conversion at low cost. Thus, the A/D converters and the associated analog I/Q (in-phase/quadrature) mixers which are employed in conventional communication receivers increase power consumption, complicate the design process (since analog designs are generally harder to test than digital designs), and increase production costs (since analog components must be tuned and/or matched).
Thus, what is required is an all digital IF-to-baseband signal converter which does not employ analog-to-digital (A/D) converters or other associated analog circuitry.